Watch here:
https://www.youtube.com/watch?v=thSTpGnWEAs
I come from a country that is living proof that public indebtedness can do little or nothing to produce growth or welfare. So, when I was an Executive Director of the World Bank and had to discuss the issue of Sustainable Debt Levels (SDL), it was a shock. Just the idea of someone calculating a Sustainable Debt Level with complex formulas was a scary thought. It reminded me of a refined torturer calculating the pain tolerance for mediocre odious credits that might forever tax a country's future.